Siege of Campus Frisii

The Siege of Campus Frisii took place in 363 AD when the Saxons invaded the lands of the rebel Frisii in the present-day Netherlands. Saxon faction heir Freawine the Cunning captured Campus Frisii from the Frisii rebels, defeating two armies and killing their leaders.

History
In 363 AD, Saxon faction heir Freawine the Cunning and an army of 1,680 Saxons from Tribus Saxones (present-day Denmark) invaded the lands of the Frisii (present-day Netherlands), hoping to crush the weak rebels. They besieged Gunderic and 930 Frisii in Campus Frisii, but found themselves facing a new threat from the south: an army of 630 Frisii troops under King Adalwolf converged on the city to reinforce it. In the battle that ensued, 870 Frisii and 62 Saxons were slain, but Adalwolf died in the battle.

Having defeated the relief force, the Saxons assaulted the city in winter 363. With only 10 losses, the Saxons killed 220 more Frisians, and captured the city from Gunderic's army. The Saxons peacefully occupied Tribus Frisii, which became their lands.